docs: def from_json(cls, data):
          """Create a DDY from a dictionary.
  
          Args:
              data = {
              "location": ladybug Location schema,
              "design_days": [] // list of ladybug DesignDay schemas}
          """
          required_keys = ('location', 'design_days')
          for key in required_keys:
              assert key in data, 'Required key "{}" is missing!'.format(key)
  
          return cls(Location.from_json(data['location']),
                     [DesignDay.from_json(des_day) for des_day in data['design_days']])